General Physical FactorsLook to these things for possible explanations of strange weight gain.

Menopause. Menopause causes many changes in the body, one possible one being a redistribution of weight in the body, moving from the hips to the midsection. Hormonal changes can also trigger greater appetite, poor sleep and depression.

Food allergies. Some food allergies, even mild ones, may be causing you to put on weight. As odd as it may sound, when you eat these foods you’re allergic to it can cause an addictive effect, making you crave the food even when you’re full.

Aging. Most people, as they age, feel their metabolisms beginning to slow down. If you’re not feeling that its as easy to lose weight as it used to be, take this into account and start working at a program that better reflects your new needs.

Depression. While depression can cause a loss of appetite in some people it can also cause an increase in others. Many eat to fill the sadness they are feeling. This emotional eating is harmful to both your mental and psychical health, so seek medical treatment if you think that this is the case for your weight gain.

Getting a cold. New studies suggest that getting a cold may actually cause you to gain weight. Certain viruses seem to increase the number of cells that develop into fat, causing a marked increase in weight over time.

Inflammation. Many lifestyle factors including stress, smoking and lack of sleep can contribute to inflammation and certain foods can have an inflammatory effect as well. This can lead to weight gains where you feel there should be none.

Your genes. While we are all responsible for our own choices, to some degree our ability to lose and maintain weight is determined by our genes. Some people will need to work harder to lose the pounds than others and will be fighting against their natural propensity for weight gain.

Building muscle. If you’ve been working out a lot and find that you’ve actually put on weight, don’t freak out. It could just be that you’ve put on muscle weight and are healthier than you were before, despite the increased weight.

Pregnancy. While this may be somewhat obvious, pregnancy is a reason for unexplained weight gain and unless you’re entirely sure it’s not the reason for yours don’t completely discount it– many pregnancies are unexpected surprises.

Water retention. Most women are familiar with the bloating that can happen when their menstrual cycles are on the horizon but there are times when this water weight gain can be more serious can caused by kidney or heart failure so it’s important to get unexplained water retention checked out.